I 3D Print Bitcoins from colorFabb Bronzefill which is a 3D Printer filament made from 80% real bronze & 20% PLA plastic. I than polish them to a shine using numerous different methods including Vibratory Bowl, Sandpaper, Steel Wool & Liquid Polish. See awesome article on this video by 3DPrint.com @ http://bit.ly/1GEN08e